Tunichromes and metal ion accumulation in tunicate blood cells

Macara, Ian G.; McLeod, G. C.; Kustin, Kenneth

doi:10.1016/0305-0491(79)90252-9

Cited by 25 publications

(23 citation statements)

References 13 publications

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“…For example, Mo is a common respiratory pigment in nitrogen fixation (Williams and Fraústo da Silva, 2002;Bellenger et al, 2008), while Ni forms a part of urease, an enzyme necessary for organisms utilizing urea as a nitrogen source (Ragsdale, 2007). Vanadyl may initially come from the vacuoles of certain marine tunicates, which accumulate V to a level that is more than 100 times greater than what is naturally present in seawater (Macara et al, 1979;Oltz et al, 1988).…”

Section: Introductionmentioning

confidence: 99%

The stable isotope composition of vanadium, nickel, and molybdenum in crude oils

Ventura

Gall

Siebert

et al. 2015

Applied Geochemistry

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Section: Introductionmentioning

confidence: 99%

The stable isotope composition of vanadium, nickel, and molybdenum in crude oils

Ventura

Gall

Siebert

et al. 2015

Applied Geochemistry

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“…Furthermore, since 1911, certain species of marine organisms called ascidians have been known to accumulate vanadium in their blood from sea water [9][10][11], yet the physiological functions and chemical structures of vanadium in the animals are not clear [9-l1]. On the other hand, the vanadate ion (+5 oxidation state of vanadium) was found to be a potent inhibitor of Nat, M+-ATPase in 1977 [12]; and as a result, physiological, biological and bioinorganic chemical interests in the biological functions of vanadium have been focused on the structures and mechanism of actions of this element in living organisms.…”

mentioning

confidence: 99%

Insulin-mimetic action of vanadyl complexes.

Tsuchiya

Nukatsuka

Kawada

et al. 1990

J. Clin. Biochem. Nutr.

110

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SummaryBlood glucose levels of streptozocin (STZ)-induced diabetic rats dropped from hyperglycemic levels to hypoglycemic levels within 24-48 h after treatment with vanadyl sulfate (VS) by intraperitoneal injection. Results of the glucose tolerance test indicated that the diabetes was completely improved by VS administration, but the plasma insulin levels were still low. Determination of both vanadyl and total vanadium in VS-treated STZ-rats suggested that the vanadyl is possibly in a pharmacologically active form. Several vanadyl complexes such as vanadyl-cysteine methyl ester (VCys), -oxalate (VOX), -malonate (VMA), -salicylaldehyde (VSA) , and -(+)-tartarate (VTA) were tested by oral administration. The order of normoglycemic effect in STZ-rats was VMA > VCys > VTA > VSA > VOX. The action of VCys was dosedependent in the range of 1-10 mg V/kg body weight, and this complex was shown to be a potent agent in restoring the normoglycemic level in STZ-induced diabetic rats.

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“…Therefore, reducing agents must play an important role in the accumulation of vanadium, because during the accumulation process V V is reduced to V III via V IV ØV V can be reduced to V IV without difficulty owing to its redox potential (VO 2 q /VO 2q : 1.00 V in a strongly acidic solution) (66). In fact, a number of biologically relevant reducing agents, including ascorbate (67-69), cysteine (70), norepinephrine (71), glutathione (69,72), oxalic acid (73), and tunichromes, as well as blood pigments isolated from a tunicate (74,75) have been found to reduce V V to V IV .…”

Section: Redox Mechanism Of Vanadiummentioning

confidence: 99%

“…Tunichromes, which are a class of hydroxy-dopa-containing tripeptides, have been isolated from some ascidian species (74,75,84,85). Because tunichromes contain pyrogallol and cathecol moieties that can have a reducing functionality, it was proposed that tunichromes participate in the reduction of vanadium in ascidians (86).…”

Section: Redox Mechanism Of Vanadiummentioning

confidence: 99%

Advances in research on the accumulation, redox behavior, and function of vanadium in ascidians

Michibata

Ueki

2010

BioMolecular Concepts

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The discovery of high levels of vanadium-containing compounds in ascidian blood cells goes back to 1911. Ascidians, which are also known as tunicates or sea squirts, belong to a subphylum of the Chordata, between the vertebrates and invertebrates. This discovery attracted the attention of an interdisciplinary group of chemists, physiologists, and biochemists, in part because of interest in the possible role of vanadium in oxygen transport as a prosthetic group in respiratory pigments, which was later shown not to be such a role, and in part because of the fact that high levels of vanadium were unknown in other organisms. The intracellular concentration of vanadium in some ascidian species can be as high as 350 mm, which is 107 times that in seawater. Vanadium ions, which are thought to be present in the +5 oxidation state in seawater, are reduced to the +3 oxidation state via the +4 oxidation state and are stored in the vacuoles of vanadium-containing cells called vanadocytes, where high levels of protons and sulfate ions are also found. Recently, many proteins and genes that might be involved in the accumulation and reduction of vanadium have been isolated. In this review, we not only trace the history of vanadium research but also describe recent advances in our understanding of the field from several viewpoints: (i) vanadium-accumulating blood cells, (ii) the energetics of vanadium accumulation, (iii) the redox mechanism of vanadium, (iv) the possible role of sulfate, and (v) the physiological roles of vanadium.

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Tunichromes and metal ion accumulation in tunicate blood cells

Cited by 25 publications

References 13 publications

The stable isotope composition of vanadium, nickel, and molybdenum in crude oils

The stable isotope composition of vanadium, nickel, and molybdenum in crude oils

Insulin-mimetic action of vanadyl complexes.

Advances in research on the accumulation, redox behavior, and function of vanadium in ascidians

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